With the aid of a diagram describe the events occurring in the neurone leading to the establishment of an action potential

Voltage-gated Na⁺ channels and Voltage-gated K⁺ channels are closed at rest, Once a stimulus is applied, the neurotransmitters activate chemically-gated (CG) channels within the cell membrane. CG Na⁺ channels open briefly, and Na⁺ ions enter the neurone, creating a local current and causing the inside of the cell membrane to be more positive than the outside. This is depolarisation, which results in a local potential. If the depolarisation is not strong enough, the channels close again and the local potential disappears. If the depolarisation is strong enough, as the Na⁺ ions enter the cell, the local potential reaches a threshold value (often reached at the axon hillock). This threshold depolarisation causes voltage-gated Na⁺ channels to open. Voltage-gated K⁺ channels also start to open. When the inside becomes more positive than the outside, the VG Na⁺ channels close and more VG K⁺ channels open. Na⁺ ions stop entering the cell and K⁺ ions exit the cell. This repolarises the cell membrane to its RMP. Depolarisation and repolarisation constitute an AP. At the end of repolarisation, the RMP becomes more negative, this is hyperpolarisation. This elevated permeability to K⁺ is very short and it allows to reestablish RMP to initiate a new action potential.